System and method for dynamic frequency allocation for packet switched services

ABSTRACT

A system, method and computer program for dynamic frequency allocation for packet switched services in which radio channels used for packet switched services may be dynamically allocated to meet quality of service (QoS) requirements utilizing a dynamic frequency and channel allocation system. The achievable throughput is estimated in the available channels. Further, the user or application is able to specify the level of service desired and the system, method and computer program will select a channel assignment to meet the desired level of service. When the channels to be assigned have been selected, the system, method and computer program will evaluate if the new channel assignment will cause excessive interference to any other ongoing connection. In such case the ongoing connection will be re-assigned to another suitable radio channel.

FIELD OF THE INVENTION

[0001] The invention relates to a system and method for dynamicfrequency allocation for packet switched services. More particularly,the invention is a system and method in which packet switched servicesmay be dynamically allocated to meet quality of service (QoS)requirements utilizing a dynamic frequency and channel allocationsystem.

BACKGROUND OF THE INVENTION

[0002] Over the relatively short history of the deployment andavailability of cellular telephones significant improvements have beenseen in the quality of service as well as the exponential increase inusage. As illustrated in FIG. 1, cellular phone service providers haveestablished cells 10 (also known as the base stations (BTS)) containinga transceiver 20 that transmits and receives signals to and from mobilestations (MS) (not shown). The cells 10 are configured so as to provideoverlapping coverage with one another so that when mobile stations movefrom one cell 10 to another cell 10, the new cell 10 seamlesslycontinues (hands over) the connection between the mobile station and thecellular network. The mobile station 210 and transceiver 20 within agiven time slot would utilize one frequency for transmission and anotherfrequency for reception. The combination of the receiving frequency andthe transmitting frequency as well as the time slot may be considered asa single channel. However, interference problems between nearby cells 10would occur when the same or adjacent frequencies are utilized by mobilestations in each cell 10.

[0003] This interference is often represented by thecarrier-to-interference ratio (C/I) which may also be referred to as thesignal-to-noise ratio. When C/I is low this would indicate either thesignal strength (C) is either low or the interference (I) is high orsome combination of the two. However, a very high C/I level would leadto less capacity in the cellular network due to fewer available channelsand would not necessarily improve QoS once the C/I level has obtained acertain minimum level.

[0004] In order to provide even levels of C/I for all mobile stations,cellular service providers have provided fixed frequency utilizationplans that provide for a frequency hopping method to be allocated foreach transceiver 20. During any given time slot through frequency andtime division multiple access (TDMA) the C/I levels may be evened outwithin a cell 10. However, transceivers 20 do not base handover andpower control decisions based on C/I levels. These decisions may oftenbe based upon such variables as field strength and bit error rate. Thetransceiver may perform some C/I measurements, but these are limited tothe receiving or uplink frequency. For nearby cells 10 only the fieldstrength measurement of the broadcast control channel frequency isdetermined by the mobile station 210. Therefore, it was not possible forone cell to effectively control C/I levels, and thus quality of service,let alone the effects that interference from nearby cells 10 may have onone another.

[0005] One solution that improved QoS was disclosed in Nokia applicationnumber PCT/FI/99/00876, herein incorporated in its entirety byreference. This Nokia application provided for dynamic optimized channelallocation (DOCA). DOCA determines the C/I level for each mobile stationand monitors it continuously that allows the cellular network todetermine whether the C/I level is within a predetermined level.Handovers from one cell 10 to another are also based upon C/I criteriaand thus the risk of service interruption is significantly reduced.However, with the exception of the broadcast control channel frequency,there is no actual frequency planning within the network and frequenciesmay be reserved as necessary to allocate channels and handovers asdetermined by the C/I analysis.

[0006] As the cellular industry has progressed no longer is cellularcommunications restricted to analog voice signals only. Today the mobilestations may be expected to carry circuit switched speech but alsodigital information such as voice over Internet protocol (VoIP), e-mailmessaging, and full-scale Internet access. With this varying type ofinformation that a cellular network must be able to handle so has comethe need for the ability to adjust the C/I level according to the typeof communications required. For example, in e-mail messaging alower-level C/I level may be tolerated since the messages are usuallyshort and communications speed is not absolutely critical. Further, aswith any IP communications, error correction occurs within a packet andpacket may be retransmitted when not received. However, any other formsof communications, such as voice, or where large volumes of data need tobe transferred and received accurately, higher levels of C/I arerequired. Nokia application number PCT/FI/01114 dealing with dynamicfrequency and channel allocation (DFCA), incorporated herein byreference, meets the needs of different users by selecting channels withthe appropriate C/I level. DFCA dynamically maintains a matrix of thequality of connection (C/I level) of all possible channels that may beallocated. This matrix enables the selection of a channel having a C/Ilevel which can best fit the user needs. Further, as other mobilestations are allocated channels in nearby cells 10 it is determined theimpact that such allocation may have on already establishedcommunications channels.

[0007] However, even though DFCA is able to provide a good QoS andmaximize the possible number of channels within a cell 10 a great dealof bandwidth is still under utilized in a circuit switched system. Inmany instances involving packet transmission as in an IP network, thenumber packets transmitted and their size is relatively small. This isparticularly evident in e-mail transmission to and from a cellular phoneand may be the case in VoIP communications. Further, in VoIPcommunications there may be periods in which no packets are transmittedsince no one is speaking. Therefore, dedicating a channel fortransmission of a relatively small or infrequent number of packets woulddefeat the advantages seen in an IP network through sharedcommunications. In an IP network, packets from different sources andusers are transmitted over the same channel or communications line to adestination that reassembles the appropriate packets to form themessage. Therefore, the communications line or channel is more fullyutilized through the sharing mechanism. However, in the case where largeamounts of data must be transmitted in the fastest possible means itwould be desirable to be able to provide a dedicated channel or channelswith high C/I values for maximum throughput.

[0008] Therefore, what is needed are a system and method that candetermined the QoS required by a mobile station and determine if sharinga channel with other mobile stations would meet the QoS required.Further, when a mobile station requires very high throughput this systemand method should dedicate a channel with a high C/I value in order tomaximize throughput. Therefore, the resources of the cellular networkshould be maximized to handle the largest number of mobile stationswhile at the same time meeting the QoS requirements of any given mobilestation.

SUMMARY OF THE INVENTION

[0009] An embodiment of the present invention provides for a system andcomputer program for dynamic channel allocation for packet switchedservices. This system and computer program has a quality of servicemanagement module to monitor requests for channel assignment from amobile station and to control the channel assignment process usingthroughput estimation and outgoing interference evaluation modules. Thequality of service module determines based on the traffic class type andthe throughput estimations if the connection can be established usingshared radio channels within the shared territory or if the connectionmust be established using dedicated channels provided in the dedicatedterritory. The throughput estimation module is used to determine theavailable user throughput in available radio channels based on theestimated C/I ratio the user would experience in different radiochannels and the existing resource usage on the same radio channels. Theoutgoing interference evaluation module is used to determine the effectof the channel assignment upon other dedicated channels already assignedwithin nearby cells based upon a C/I ratio. When required, the outgoinginterference evaluation module triggers handovers in order to moveendangered connections on dedicated channels that may be adverselyaffected by the new channel to other dedicated or shared channels.

[0010] Further, an embodiment of the present invention is a method ofdynamic channel allocation for packet switched services. This methodstarts by allocating frequencies to a plurality of transceiver unitswithin cells based upon calculating a C/I ratio for the cell with theaddition of each frequency or by any other channel allocation methodthat aims to minimize the interference in the network. These assignedfrequencies are to be used in the shared territory time slots wheneverthe transceiver unit carries shared territory time slots. Transmittingthe frequencies to each of the plurality of transceiver units. Receivinga request for a channel assignment from a mobile station. Thendetermining a traffic class type for the channel assignment, wherein thetraffic class type is either best effort or guaranteed throughput.Estimating the available user throughput based upon a C/I ratio for thechannel assignment in the available shared territory radio channels andassigning the connection to a shared radio channel with the bestthroughput if the traffic class is best effort. Further, assigning thechannel assignment to a dedicated channel when the traffic class type isguaranteed throughput and a shared channel assignment would generateinadequate throughput for the mobile station. Rejecting the channelassignment and triggering a re-negotiation of the quality of serviceparameters when the required throughput rate cannot be achieved in theavailable shared or dedicated channels when the traffic class type isguaranteed throughput. In all cases, evaluating the outgoinginterference that may result from the channel assignment in the sharedor the dedicated territory based upon the C/I ratio that the affecteddedicated territory connections in nearby cells are estimated to besubjected to as a result of the channel assignment. Relocating theaffected connections to other channels by means of handovers orrejecting the channel assignment when the estimated resulting C/I ratiodoes not exceed a predetermined value that may depend on the quality ofservice requirements of each affected connection.

[0011] These and other features of this device, method and computerprogram will become more apparent from the following description whentaken in connection with the accompanying drawings that show, forpurposes of illustration only, examples in accordance with the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and a better understanding of the present inventionwill become apparent from the following detailed description ofexemplary embodiments and the claims when read in connection with theaccompanying drawings, all forming a part of the disclosure of thisinvention. While the foregoing and following written and illustrateddisclosure focuses on disclosing example embodiments of the invention,it should be understood that the same is by way of illustration andexample only and the invention is not limited thereto. The spirit andscope of the present invention are limited only by the terms of theappended claims.

[0013] The following represents brief descriptions of the drawings,wherein:

[0014]FIG. 1 is an example configuration of a cellular network;

[0015]FIG. 2 is a systems architecture diagram in an example embodimentof the present invention;

[0016]FIG. 3 is an illustration of a cell having two different C/Ilevels associated with mobile stations in an example embodiment of thepresent invention;

[0017]FIG. 4 is an illustration of the radio resource managementstrategy diagram based on the shared and dedicated channel territorieswithin the transceiver units;

[0018]FIG. 5 is an example modular configuration diagram of the dynamicfrequency management system employed in an example embodiment of thepresent invention;

[0019]FIG. 6 is an example flowchart illustrating the operationsperformed by the frequency assignment module 510, shown in FIG. 5;

[0020]FIG. 7 is an example flowchart illustrating one possible frequencyallocation algorithm i.e. the operations performed in the block 610,shown in FIG. 6;

[0021]FIG. 8 is an example flowchart illustrating the operationsperformed by the QoS management module 540, shown in FIG. 5;

[0022]FIG. 9 is an example flowchart illustrating the operationsperformed by the throughput estimation module 520, shown in FIG. 5; and

[0023]FIG. 10 is an example flowchart illustrating the operationsperformed in the C/I estimation module in block 925 and 975 shown inFIG. 9;

[0024]FIG. 11 is an example flowchart illustrating the operationsperformed by the outgoing interference evaluation module 530 shown inFIG. 5.

DETAILED DESCRIPTION

[0025] Before beginning a detailed description of the subject invention,mention of the following is in order. When appropriate, like referencenumerals and characters maybe used to designate identical, correspondingor similar components in differing figure drawings. Further, in thedetailed description to follow, exemplary sizes/models/values/ranges maybe given, although the present invention is not limited to the same.

[0026]FIG. 2 is a systems architecture diagram in an example embodimentof the present invention. As previously discussed cell 10 contains atransceiver 20 which may communicate with a mobile station 210 that isin range of transceiver 20. Cell 10 is controlled by a base stationcontroller (BSC) 230 that determines how the transceivers transmissionsmust be adjusted to align all transmissions within a time slot. Thiswould thereby synchronize the entire cellular network, as exemplifiedand illustrated in FIG. 1. In turn one or more base station controllers230 would be connected to a mobile switching center (MSC) 240 thatenables a mobile station 210 to communicate to another mobile station210 in another cell 10 or to a telephone or other device connected tothe public switched telephone network (PSTN) 250 or an Internet protocol(IP) network 260 such as but not limited to the Internet. In turn the IPnetwork 260 would be connected to a content provider (CP) 270 whichwould supply content desired by the user of the mobile station 210. Aswould be appreciated by one of ordinary skill in the art, the preciseconfiguration illustrated in FIG. 2 may vary dependent upon thecomplexity of the cellular network. For example, it may be possible toeliminate or reduce the number of MSC's 240 and have a BSC 230 directlycommunicate to the PSTN 250 or the IP network 260.

[0027]FIG. 3 is an illustration of a cell 10 having two different C/Ilevels 300 and 310 associated with mobile stations 210 in an exampleembodiment of the present invention. This illustration is provided toshow that C/I levels may be located physically anywhere within a cell10. The determination whether a particular C/I level 300 or 310 is highor low is based upon transceiver 20 in conjunction with BSC 230 and anyinterference received from nearby cells 10.

[0028]FIG. 4 is an illustration of the transceiver 20 comprising ofmultiple transceiver units each providing a carrier frequency used inthe cell that is further divided into several time slots that alltogether constitute a TDMA frame. Each time slot within each transceiverunit 410 to 430 may belong to one of the shared territories 435 to 445or to the dedicated territory 450. For all shared territory time slotseach transceiver unit uses the pre-allocated frequency that has beenassigned to it by the frequency assignment module 510 shown in FIG. 5.For each of the dedicated territory time slots each transceiver unitwill use the dynamically assigned frequency that has been selected basedon the C/I estimations by the DFCA algorithm. The shared territory timeslots together with the pre-allocated frequency form a set of sharedradio channels that can be assigned to several mobile stations 210simultaneously. Typically the usage of the shared radio channel iscontrolled by a packet scheduling function that decides which user datais to be transmitted on the shared channel at any one time. The sharedchannels are advantageous as the multiplexing of several data streamsprovides the possibility to achieve a very efficient use of the radioresource. However, since the shared channels use a pre-allocatedfrequency the C/I in each shared territory time slot is fixed. This, andthe time slot capacity used to serve existing connections on the sharedterritory may in some cases make it impossible to achieve the requiredthroughput. In this kind of situation the dedicated territory may beutilized for the connection. A dedicated territory time slot can be usedfor only one connection at the time and it does not have a pre-allocatedfrequency associated with it. Instead, the frequency used In thededicated territory time slot is selected from the available frequencyband by the DFCA algorithm so that the C/I can be maximized. Thisgenerally leads to a better possibility to find a radio channel withsufficient C/I in order to provide the required throughput. This isfurther helped by the fact that the dedicated territory time slots arededicated to one connection only, so the whole time slots capacity isavailable to the user. In addition to the selected packet switched dataconnections, all the circuit switched speech and circuit switched dataconnections are assigned to the radio channels in the dedicatedterritory by the DFCA algorithm based on the C/I criteria.

[0029] The modular configuration diagrams shown in FIG. 5 as well as theflowcharts shown in FIGS. 6 through 11 contain software, firmware,hardware, processes or operations that correspond, for example, to code,sections of code, instructions, code segments, commands, objects, or thelike, of a computer program that is embodied, for example, on a storagemedium such as floppy disk, CD Rom, EP Rom, RAM, hard disk, etc.Further, the computer program can be written in any language such as,but not limited to, for example C++.

[0030]FIG. 5 is an example modular configuration diagram of the dynamicfrequency management system 500 employed in an example embodiment of thepresent invention. The dynamic frequency management system 500 isutilized to control channel assignment in a plurality of cells 10 so asto provide a maximum number of mobile stations 210 access to thecellular network while maintaining an appropriate level of QoS usingdedicated and shared channels. The dynamic frequency management module500 comprises at least four major modules and is utilized to assignfrequencies/channels to mobile stations 210, determine estimatedthroughput availability and outgoing interference, and based on thatestimated throughput and outgoing interference as well as the quality ofservice desired establish the appropriate channel connection. Afrequency assignment module 510, as discussed in further detail withrespect to FIG. 6, is utilized to assign shared territory frequenciesfor each transceiver unit 410 to 430 in each respective cell 10 from thefrequency pool available. The resulting shared territory frequencies arestored in the shared territory frequency table 515. The throughputestimation module 520, as discussed in further detail with respect toFIG. 9, would monitor any incoming interference and the existing timeslot capacities to derive a throughput estimations that may affect a newchannel assignment for a mobile station 210. The outgoing interferenceevaluation module 530, as discussed in further detail with respect toFIG. 11, would evaluate the outgoing interference that may affect anydedicated territory channels assigned in any nearby cells 10. The QoSmanagement module 540, as discussed in further detail with respect toFIG. 8, would determine the type of service required by a particularmobile station 210 and select from the available channels in order toprovide the QoS desired. The dynamic frequency management module 500 inturn interfaces to and updates a background interference matrix (BIM)550 and a channel usage table 560. Network configuration data, frequencyallocations and steering parameters may be contained in anotherdatabase. The BIM 550 contains measurement based statistical C/I valuesthat represent statistically expected C/I values between any two cellsin the network. This statistical C/I data forms a cell dependency matrixthat can be used as an input for the frequency assignment module.

[0031]FIG. 6 is an example flowchart illustrating the operationsperformed by the frequency assignment module 510, shown in FIG. 5. Thefrequency assignment module 510 begins execution in operation 600 andimmediately proceeds to operation 605. In operation 605 the BIM 550 isaccessed to determine the cell dependency matrix and other suitabledatabase is accessed to determine the cell 10 and transceiver 20configuration data, the frequencies available and allocation steeringparameters. Operation 610 comprises of an execution of a frequencyallocation algorithm that assigns the available frequencies to thetransceiver units 410 to 430 in FIG. 4 in a way that aims to minimizethe interference in the network. These assigned frequencies are thenused for the shared territory time slots within each transceiver unit.The frequency allocation algorithm may be implemented in many ways andseveral well known solutions exist. Once the frequency allocationalgorithm 610 has been executed, then processing proceeds to operation615, where the frequency parameters are transmitted to each cell 10 andtransceiver 20 within the cellular network. Thereafter, processingproceeds operation 620 where processing terminates.

[0032]FIG. 7 presents an example flowchart of a possible frequencyallocation algorithm that may be used to realize the operation requiredin block 610 in FIG. 6. The frequency allocation algorithm beginsexecution in operation 700. Thereafter, in operation 705 a transceiver20 TRX is selected. Thereafter in operation 710 a cell 10 is selectedand in operation 715 a frequency pair comprising a sending and receivingfrequency, is selected. In operation 720, a C/I ratio is calculated forthe selected frequency within the particular cell 10. Thereafter, inoperation 725 all nearby cells are checked for possible interference dueto the possible allocation of the frequency within this particular cell10. Operation 730 comprises of a check if all available frequencies havebeen evaluated. If not, the execution returns to operation 715. If allavailable frequencies have been processed then execution proceeds tooperation 735. In operation 735 the frequency pair that minimizes theinterference in the network is selected. Processing then proceeds tooperation 740 where the shared territory frequency table is updated withthe selected frequency. Processing then proceeds to operation 745 whereit is then determined if all cells 10 have been processed. If all cells10 have not been processed then processing loops back to operation 710.Thereafter, if all cells 10 have been processed then processing proceedsto operation 750 where it is determined if all transceiver 20 units havebeen processed. If all transceiver units have not been processed thenprocessing loops back to operation 705. Otherwise, processing proceedsto operation 755 where processing terminates.

[0033]FIG. 8 is an example flowchart illustrating the operationsperformed by the QoS management module 540, shown in FIG. 5. The QOSmanagement module 540 begins processing in operation 800 and immediatelyproceeds to operation 805. In operation 805 the user's QoS requirements,such as throughput as well as the delay and traffic class are accessed.In operation 810, the available throughput is checked for all theavailable shared time slot (TSL) combinations that are supported by themobile station 210 and the network. The throughput estimation procedure810 is presented with more detail in FIG. 9. Thereafter in operation 815the allowed time slot combination with the best throughput is selected.Processing then proceeds to operation 820 where the traffic class typeis determined. In this embodiment, two possible traffic classes areprovided. Specifically, best effort throughput and guaranteedthroughput. However, as would be appreciated by one of ordinary skill inthe art any number of traffic classes may be created dependent upon theneeds of the user and the capabilities of the cellular network.

[0034] Still referring to FIG. 8, if the traffic class provides forguaranteed throughput then processing proceeds to operation 825. Inoperation 825 it is determined if the throughput requirement is met. Ifthe throughput requirement is met, then processing proceeds to operation835. In addition, if the traffic class is a best effort throughput type,then processing proceeds to operation 835 also. In operation 835 theconnection is assigned to the previously determined shared territoryallowed time slot combination that provides the highest throughput andthe channel usage table 560 in FIG. 5 is updated accordingly.Thereafter, processing proceeds to operation 840 where the outgoinginterference caused by the new channel assignment is evaluated. If thenew assignment is found to cause excessive interference to any existingconnection in nearby cells, the existing connection is relocated toanother radio channel by handover procedure. The outgoing interferenceevaluation procedure 840 is presented in more detail in FIG. 11. Afterthe outgoing interference has been evaluated the execution proceeds tooperation 845 where the channel assignment procedure for the packetswitched connection ends.

[0035] Still referring to FIG. 8, if in operation 825 the throughput isnot met then processing proceeds to operation 830. In operation 830 theavailable user throughput is estimated in all available dedicatedterritory time slots for all available frequencies. This operation 830is described in further detail in FIG. 9. The execution then proceeds tooperation 835 where the time slot counter n is reset. This is followedby operation 850 where the number of dedicated territory time slots tobe considered for allocation n is incremented by one. Processing thenproceeds to operation 855 where the best available throughput using asupported configuration of n time slots for the radio channel isdetermined based on the throughput estimations obtained previously inoperation 830. Thereafter, in operation 860, it is determined if thethroughput requirement is met. If the throughput requirement is met inoperation 860 then processing proceeds to operation 865 where thechannel is allocated in the dedicated territory using n time slots andthe channel usage table 560 in FIG. 5 is updated correspondingly.Thereafter, processing proceeds to operation 840 where the outgoinginterference is evaluated as described before and finally the processingproceeds to operation 845 where processing terminates.

[0036] Still referring to FIG. 8, if in operation 860 it is determinedthat throughput cannot be met then processing proceeds to operation 870.In operation 870 it is determined whether the number of requiredtimeslots exceeds the capacity/capabilities of the mobile station 210 orthe cell 10. If the number of timeslots required do not exceed suchcapabilities then processing returns to operation 850. However, if thenumber of timeslots required do exceed such capabilities then processingproceeds to operation 880 where the quality of service requirementsrequested are renegotiated. This may entail requesting the user or anapplication requiring the information transfer within the mobile station210 or on the network side to accept, at least temporarily, a lower thandesired level of service. Thereafter, processing returns to operation805.

[0037]FIG. 9 is an example flowchart illustrating the operationsperformed by the throughput estimation module 520, shown in FIG. 5. Thethroughput estimation module 520 begins execution in operation 900 andimmediately proceeds to operation 905. In operation 905, the territoryfor which the throughput estimation is to be performed is checked. Ifthe territory to be evaluated is a shared territory then the processingproceeds to operation 910. In operation 910 the shared territoryfrequency table 515 and the channel usage table 560 are accessed toretrieve information indicating which time slots in the cell 10 arecurrently belonging to the shared territory and what are thepre-allocated shared territory frequencies used in those time slots.Processing then proceeds to operation 915 where one of the sharedterritories in the current cell 10 is selected for examination.Processing then proceeds to operation 920 where one of the time slotswithin the selected shared territory is selected for examination.Thereafter, the processing proceeds to operation 925 where the C/I thatthe user would be subjected to in the current time slot is estimated.The C/I estimation procedure in operation 925 is discussed in moredetail in FIG. 10. The processing then proceeds to operation 930 wherethe estimated C/I is used to derive an estimation of the maximumavailable throughput that could be achieved in this time slot. Thisestimation can be achieved for example by utilizing C/I in throughputmapping tables. This operation is followed by operation 935 where thechannel usage table 560 is accessed to determine how much of the timeslot resource is already being utilized by other connections sharing thesame time slot. Thereafter, processing proceeds to operation 940 wherethe estimated maximum time slot throughout is adjusted by taking intoaccount the share of the time slot resources already being used by otherconnections. As a result an estimate of the available user throughput inthe current time slot is derived. Execution then proceeds to operation945 where it is determined if all the time slots within the currentshared territory have been examined. If all the time slots in thecurrent shared territory have not been processed then the processingreturns to operation 920, otherwise processing proceeds to operation950. In operation 950 it is determined if all the shared territories inthe current cell 10 have been processed. If all the shared territoriesin the current cell 10 have not been processed then the processingreturns to operation 915, otherwise execution proceeds to operation 955where it terminates.

[0038] Still referring to FIG. 9, if in operation 905 it is determinedthat the throughput estimation is to be performed to a dedicatedterritory then processing proceeds to operation 960. In operation 960the channel usage table 560 is accessed to retrieve informationindicating which time slots in the cell 10 currently belong to thededicated territory and what are the frequencies allowed to be used fordedicated territory connections in the current cell 10. Processing thenproceeds to operation 965 where one of the frequencies available forusage in the dedicated territory is selected for evaluation. Thereafterprocessing then proceeds to operation 970 where one of the availablededicated territory time slots is selected for evaluation. Processingthen proceeds to operation 975 where the C/I that the user would besubjected to in the current time slot is estimated. The C/I estimationprocedure in operation 975 is discussed in more detail in FIG. 10.Thereafter, the processing proceeds to operation 980 where the userthroughout is estimated based on the previously estimated C/I ratio.This can be performed for example by utilizing C/I in throughput mappingtables. The processing then proceeds to operation 985 where it isdetermined if all dedicated territory time slots in the current cellhave been processed. If all the dedicated territory time slots in thecurrent cell have not been processed then the processing returns tooperation 970. If all the dedicated territory time slots in the currentcell have been processed then execution proceeds to operation 990. Inoperation 990 it is determined if all the frequencies available fordedicated territory in the current cell 10 have been processed. If allsuch frequencies have not been processed then processing returns tooperation 965, else the processing proceeds to operation 995 where it isterminated.

[0039]FIG. 10 is an example flowchart illustrating the operationsperformed by the C/I estimation module illustrated in operations 925 and975, shown in FIG. 9. The C/I estimation module begins execution inoperation 1000 and immediately proceeds to operation 1005. In operation1005 the information of the current frequency and the current time slotthat are to be evaluated are accessed. Processing then proceeds tooperation 1010 where a potentially interfering nearby cells 10 isselected from the BIM 550. Thereafter, the processing proceeds tooperation 1015. In operation 1015 it is determined by accessing thechannel usage table 560 if the potentially interfering cell has ongoingconnections using the current time slot and the current frequency or afrequency adjacent to the current frequency. If no such ongoingconnections exist then processing proceeds to operation 1055.Else theprocessing proceeds to operation 1020. In operation 1020 it is checkedif the signal level of the selected interfering cell 10 is reported in arecent measurement report received from the mobile station 210 alsocontaining the received signal level of the serving cell 10. Thisdownlink measurement report may be contained in the channel usage table560 or other suitable database. If it is determined that the interferingcell 10 is reported in the MR then processing proceeds to operation 1030where the C/I ratio is set equal to that contained in the measurementreport.

[0040] Still referring to FIG. 10, if in operation 1020 it is determinedthat the interfering cell signal level cell 10 is not reported in themeasurement report then processing proceeds to operation 1025 where theC/I ratio is set equal to that found in the BIM 550. Either fromoperation 1025 or operation 1030 processing then proceeds to operation1035 where the type of interference introduced is determined. If theinterference is due to an adjacent frequency, then processing proceedsto operation 1040 where the C/I ratio is incremented by an adjacentchannel protection margin that is a predetermined value. This adjacentchannel protection margin is selected to reduce the C/I ratio to a levelthat corresponds to the detrimental impact of the adjacent channelinterference if the interference would be regarded as co-channelinterference. However, if in operation 1035 the type of interference isdetermined to be co-channel interference then processing proceeds tooperation 1045 from either operation 1035 or 1040. In operation 1045 theC/I ratio is reduced by a transmission power level reduction value thatcorresponds to the current transmission power reduction implemented inthe interfering connection by the power control function if it is used.This power reduction value can be available in the channel usage table560 where it is updated by the power control function. This adjustmentof the C/I ratio ensures that the impact of the possible power controlfunctionality is taken into account in the C/I estimation procedure.Thereafter, processing proceeds to operation 1050 where the interferencecontribution of the currently examined interfering connection is summedto the overall interference level impacting the time slots and frequencythat are currently being evaluated. Processing then proceeds tooperation 1055 where it is determined if all the potentially interferingcells have been processed. If all the potentially interfering cells havenot been processed then processing loops back to operation 1010.However, if all cells 10 have been processed then processing proceeds tooperation 1060 where processing terminates.

[0041]FIG. 11 is an example flowchart illustrating the operationsperformed by the outgoing interference evaluation module 530, shown inFIG. 5. The outgoing interference evaluation module 530 begins executionin operation 1100 and immediately proceeds to operation 1105. Inoperation 1105, the information of the cell 10, the time slots and thefrequency that are to be used in the new channel assignment is accessed.Processing the proceeds to operation 1110 where one of the time slotsthat is to be used for the new connection is selected. Thereafter, theprocessing proceeds to operation 1115 where one of the potentiallyinterfered nearby cells is selected for examination. The information ofthe potentially interfered nearby cells is available in BIM 550. Inoperation 1120 it is determined by accessing the channel usage table 560if the potentially interfered cell has ongoing connections using thecurrent time slot and the frequency used by the new connection or afrequency adjacent to the frequency used by the new connection. If nosuch ongoing connections exist then processing proceeds to operation1170. Else the operation proceeds to operation 1125. In operation 1125it is determined if the cell 10 where the new channel assignment isbeing performed is reported in the downlink measurement report (MR) ofthe connection that would be interfered by the new connection. Thisdownlink measurement report may be contained in the frequency usagetable 560 or other suitable database. If it is determined that the cell10 where the new channel assignment is being performed is reported inthe measurement report then processing proceeds to operation 1135 wherethe C/I ratio is set equal to that contained in the measurement reportof the interfered connection.

[0042] Still referring to FIG. 11, if in operation 1125 it is determinedthat cell 10 where the new channel assignment is being performed is notreported in the MR then processing proceeds to operation 1130 where theC/I ratio is set equal to that found in the BIM 550. Either fromoperation 1130 or operation 1135 processing then proceeds to operation1140 where it is identified if the interference caused to the existingconnection is co-channel interference or adjacent channel interference.If the interference is due to an adjacent channel then processingproceeds to operation 1150 where the C/I ratio is incremented by anadjacent channel protection margin that is a predetermined value. Thisadjacent channel protection margin is selected to reduce the C/I ratioto a level corresponds to the detrimental impact of the adjacent channelinterference if the interference would be regarded as co-channelinterference. However, if in operation 1140 the type of interference isdetermined to be co-channel interference then processing proceeds tooperation 1155 from either operations 1140 or 1150. In operation 745 theC/I ratio is reduced by a transmission power level reduction value thatcorresponds to the current transmission power reduction implemented inthe interfering connection by the power control function if it is used.This power reduction value can be available in the channel usage table560 where it is updated by the power control function. This adjustmentof the C/I ratio ensures that the impact of the possible power controlfunctionality is taken into account in the C/I estimation procedure.Processing then proceeds to operation 1160 where it is determined if thetotal C/I ratio exceeds or equals the permitted C/I ratio limit that isthe minimum C/I ratio required for acceptable QoS for the interferedconnection. If the C/I ratio is not greater than or equal to the C/Iratio limit then processing proceeds to operation 1165 where a handoveris triggered in order to move the interfered connection to anotherchannel. Either from operation 1160 or 1165 the processing then proceedsto operation 1170. In operation 1170 it is determined if all thepotentially interfered cells 10 have been processed. If all potentiallyinterfered cells 10 have not been processed then processing loops backto operation 1115. However, if all potentially interfered cells 10 havebeen processed then processing proceeds to operation 1175. In operation1175, it is determined if all the time slots to be used for the newchannel have been processed. If all such time slots have not beenprocessed then processing loops back to operation 1110. Else, theprocessing proceeds to operation 1180 where it terminates.

[0043] Using the foregoing embodiments of the present invention, amobile station of service provider can offer customers a wide array ofservices in a cellular network. For example, many customers may wish tosimply have voice capability and e-mail capability on their mobilestations 210. The service provider could tailor a package so thatdedicated channels would be allocated for voice transmission whileshared channels would be utilized for e-mail. Other customers mayspecify a higher end service in which for example a streaming video oraudio is required and therefore higher throughput with a guarantee of acertain minimum achievable throughput is needed. In this case theservice provider could either supply a dedicated channel or sharedchannel with a limited number of users on it and a high C/I levelspecified. Further, the allocation of the types of channels may bedynamic based on traffic conditions and user needs. Therefore, thecellular network service provider can offer a wider array of enhancedservices utilizing the same bandwidth with currently available for anygiven cell 10.

[0044] While we have shown and described only a few examples herein, itis understood that numerous changes and modifications as known to thoseskilled in the art could be made to the present invention. For example,the dynamic frequency management system 500 may be distributed anywherewithin a cellular network or contain within the mobile station 210,transceiver 20, cell 10, BSC 230 or MSC 240. In addition, as previouslydescribed in DFCA, Nokia application number PCT/FI/01114, cyclicalfrequency hopping capability may be utilized in the present invention.Simply for the sake of simplicity the present invention has beendescribed with out the utilization of cyclical frequency hopping.However, cyclical frequency hopping improves the quality of servicereception noticed by the user at the mobile station. Thus, addingcyclical frequency hopping to the present invention would also improvethe quality of service in the present invention. As described above,without cyclical frequency hopping, a radio channel is defined by thetime slots and the frequency. However, with cyclical frequency hoppingthe frequency is replaced by the frequency list and the phase in thehopping sequence. The implementation of cyclical frequency hopping maydone by simply substituting the term “frequency” in the specificationfor a “frequency list” and “the phase in the hopping sequence pair”.Therefore, we do not wish to be limited to the details shown anddescribed herein, but intend to cover all such changes modifications asare encompassed by the scope of the appended claims.

We claim:
 1. A system for dynamic channel allocation for packet switchedservices, comprising: a throughput estimation module to determine whenpossible incoming interference with other assigned channels may occurand to derive time slot throughput estimates; an outgoing interferenceevaluation module to determine the effect of the channel assignment uponother channels already assigned within a cell and within nearby cellsbased upon a C/I ratio; and a QoS management module to choose a sharedor a dedicated channel for the connection based upon a traffic classtype associated with the mobile station or the service or theapplication requiring the information transfer and throughputrequirements of the channel assignment.
 2. The system recited in claim1, wherein the traffic class type comprises: a best effort traffic classtype that will cause the channel assignment to be made to a sharedchannel; and a guaranteed traffic class type that will cause the channelassignment to be made to a shared channel when adequate throughputexists on the shared channel and will cause the channel assignment to bemade to dedicated channel when adequate throughput does not exist on theshared channel.
 3. The system recited in claim 2, further comprising: afrequency assignment module to assign frequencies used for the sharedchannels for each of a plurality of transceiver units based uponmaximizing the C/I ratio for each assigned frequency within each cell.4. The system recited in claim 3, wherein the frequency assignmentmodule assigned channels based upon a heuristic algorithm.
 5. The systemrecited in claim 2, wherein the QoS management module will assign foreach connection with a guaranteed throughput requirement a minimumnumber of dedicated channels needed to satisfy the connection throughputrequirement if the required throughput exceeds the capabilities of anyshared channels.
 6. The system recited in claim 5, wherein when theassignment of a required number of dedicated channels exceeds thecapacity of the cell or the capability of the mobile station the qualityof the service requirements are renegotiated for the connection.
 7. Thesystem recited in claim 2, wherein the throughput estimation module willproduce throughput estimates for the available radio channels based onthe estimated C/I and the available channel capacity to be used in thequality of service module for channel assignment of the decisions. 8.The system recited in claim 2, wherein the outgoing interferenceevaluation module will evaluate the level of interference a new channelassignment is expected to cause on the other channels that have alreadybeen assigned to connections in a serving cell and the nearby cells. 9.The system recited in claim 8, wherein the outgoing interferenceevaluation module may trigger a radio channel re-assignment for theongoing connections in the dedicated territory that are expected to beadversely affected based on a C/I criteria by the interference resultingfrom the new channel assignment.
 10. A method of dynamic channelallocation for packet switched services, comprising: dividing thetransceiver unit resources in a cell to shared channel resources forminga shared territory and dedicated channel resources forming a dedicatedterritory; allocating frequencies for the shared territories to aplurality of cells based upon minimizing the interference between theshared territories among the plurality of cells. transmitting thefrequencies to each of the plurality of cells; receiving a request for achannel assignment from a mobile station or a core network, wherein achannel assignment comprises two of the frequencies; estimating theachievable throughputs in each of the possible radio channels based onthe estimated C/I and the channel capacity already used by otherconnections; determining a traffic class type for the channelassignment, wherein the traffic class type is either best effort orguaranteed; assigning the shared channel providing the highest estimatedthroughput when the traffic class type is best effort; assigning adedicated channel able to provide the required throughput when thetraffic class type is guaranteed and a shared channel assignment wouldgenerate inadequate throughput for the mobile station; evaluatingoutgoing interference that may result from the channel assignmentimpacting any existing connections in the serving cell or the nearbycells based upon the estimated post-assignment C/I ratio for eachexisting connection; and initiating a channel re-assignment for theexisting connections for which the C/I ratio is estimated not to exceeda predetermined value.
 11. The method as recited in claim 10, furthercomprising: renegotiating the quality of service for the connection whenthe estimated throughput available in all the available shared anddedicated channel combinations that are within the capabilities of themobile station and the cell is insufficient to satisfy the requiredthroughput.
 12. The method as recited in claim 10, wherein identifyingincoming interference further comprises: determining whether theincoming interference is either due to an adjacent channel or acochannel.
 13. The method recited in claim 11, wherein the renegotiatingall the quality of service for the mobile station comprises offering themobile station a lower quality of service.
 14. A computer programstorable on a computer readable medium and executable by computer fordynamic channel allocation for packet switched services, comprising: athroughput estimation code segment to determine when possibleinterference with other assigned channels may occur and derive athroughput estimation for all available radio channels based upon atotal C/I ratio; an outgoing interference evaluation code segment todetermine the effect of the channel assignment upon other channelsalready assigned within a cell and within nearby cells based upon a C/Iratio; and a QoS management code segment to monitor requests for channelassignment from the mobile station or the core network, allocate thechannel assignment to either a dedicated channel or a shared channelbased upon a traffic class type associated with the mobile station thethroughput requirements of the channel assignment and the estimatedavailable throughput on available shared and dedicated channels.
 15. Thecomputer program recited in claim 14, wherein the traffic class typecomprises: a best effort traffic class type that will cause the channelassignment to be made to a shared channel; and a guaranteed trafficclass type that will cause the channel assignment to be made to a sharedchannel when adequate throughput exists on the shared channel and willcause the channel assignment to be made to dedicated channel whenadequate throughput does not exist on the shared channel.
 16. Thecomputer program recited in claim 15, further comprising: a frequencyassignment code segment to assign channels for each of the sharedterritories in a plurality of cells based upon calculating a C/I ratiofor each cell.
 17. The computer program recited in claim 18 wherein thefrequency assignment code segment assigned channels based upon aheuristic algorithm.
 18. The computer program recited in claim 15,wherein the QoS management code segment will minimize the number ofassigned dedicated channels to a minimum required to provide therequested throughput when the throughput required for the channelassignment exceeds the capabilities of any shared channels.
 19. Thecomputer program recited in claim 18, wherein when the estimatedthroughput available in any of the available dedicated channelssupported by the mobile station and the cell is not sufficient tosatisfy the requested quality of service requirements the renegotiationof the quality of service requirements for the connection is initiated.20. The computer program recited in claim 14, wherein the outgoinginterference evaluation code segment will trigger a re-assignment of achannel when the estimated C/I ratio is insufficient to maintain therequested throughput for an existing connection.